This invention relates to a system controlling communication between electronic devices.
In some cases, separate electronic control devices including microcomputers are connected via a common data link to provide communication therebetween. For example, in some modern automotive vehicles, separate microcomputer-based control devices such as an engine control unit, a transmission control unit, and a shock absorber control unit, are connected via a common data link to communicate with each other. In such an automotive communication system, sensors detecting control parameters are generally connected to nearest control units respectively. Control data signals derived through the sensors are transmitted between the control units via the common data link. If the common data link fails, a serious problem can arise.